1. Field of the Invention
The present invention relates to a feeder tube for outputting a liquid along at least part of its length.
The present invention also relates to an apparatus for enabling heat transfer between a first fluid and an elongate element. Such an apparatus may be used to exchange heat between two systems, the first fluid forming part of the first system and the elongate element forming part of the second system. The second system may include a second fluid flowing through the elongate element so that heat transfer between the first and second fluids can be effected. The apparatus may also be incorporated in an apparatus used to evaporate the first fluid in liquid form.
2. Description of the Prior Art
FIG. 1 shows a prior art apparatus 2 used to evaporate a fluid 4 which is in liquid form. The apparatus 2 includes a plurality of heating elements 6 which extend along a drum 8. The drum 8 is at least partially filled with the fluid 4 so that the heating elements 6 are covered. When the heating elements are switched on, the liquid 4 is evaporated, the vapour passing out of the drum 8 through an outlet 9. Such an apparatus is an inefficient heat exchanger because the majority of the liquid 4 is not in contact with the heating surfaces of the heating elements 6.
FIG. 2 shows a second prior art apparatus 10 which comprises a plurality of heating elements 12 extending along a drum 14. Liquid is introduced into the drum 14 via a plurality of spray nozzles 16 on the internal surface of the drum 14. As the liquid is sprayed into the drum 14, it forms a film of liquid on the external surfaces of the heating elements 12. Accordingly, the heat exchange between the heating elements 5 and the liquid is improved in comparison with the embodiment of FIG. 1.